An electronic component mounting system having a plurality of production lines is managed by a production order plan for allocating each job group of a plurality of job groups to a production line where the corresponding job group is performed.
PTL 1 discloses a managing method for giving top priority information to a specific job group based on experience and know-how of a person who creates a production order plan when allocating the job group having the same production due date to the production line. The managing method preferentially allocates a job group to which the top priority information is given, to the production line.